Six things you should know about hearing loss and dementia
By Dr. Peter Russell B.A., M.Sc., Au.D. Aud-Reg,
Hear Right Canada Nova Scotia Inc.
September is World Alzheimer’s Month. Are you concerned about dementia, either for you or for a loved one? If so, you are not the only one. Dementia has affected many families, including mine. This article reviews six things you should know about hearing loss and dementia.
#1 Dementia and Alzheimer’s
The Alzheimer’s Society of Canada describes dementia as a general term for symptoms that are caused by disorders of the brain. Common symptoms of dementia include (1) short-term and long-term memory loss, (2) difficulty with problem solving, thinking or language that affects everyday activities, and (3) changes in mood and behaviour. Alzheimer’s is the most common form of dementia. Alzheimer’s involves a build up of amyloid-beta plaques and tangled neural fibres. The plaques and tangles cause brain cells to lose function and die, leading to dementia. Symptoms of dementia and Alzheimer’s depend upon the area of the brain affected, and the progression of the disease.
#2 Leading cause of hearing loss in mid-life
The most common type of permanent hearing loss that we develop as adults is called sensorineural. This type of hearing loss is most often the result of damage to tiny hair cells in the inner ear. Damage to hair cells can be due to aging, exposure to loud noise, and health conditions such as diabetes, cardiovascular disease, and thyroid disease. These hearing losses progress gradually, and usually affect the higher frequencies before the lower frequencies. Hair cell damage also can cause tinnitus (ringing or other sounds in the ears) and sensitivity to loud sounds.
#3 Incidence of dementia and 50+ hearing loss
Incidence of hearing loss and dementia increases as we age. The Alzheimer Society of Canada recently published a landmark study that reported over 600,000 Canadians currently have dementia. By 2030, they project that Canadians with dementia will increase to 1 million and by 2050 cases will increase to 1.7 million. According to Statistics Canada (2021), the percentage of hearing loss for 50+ age groups is as follows:
Age 50-59: 51 percent
Age 60 to 69: 77 percent
Age 70-79: 94 percent
#4 Reducing Risk: Mid-life hearing loss is a modifiable risk factor for dementia
The Alzheimer Society study outlined actions to help reduce the risk of developing dementia. Based upon a study from The Lancet in 2020, they provided a list of 12 modifiable risk factors that may prevent or delay up to 40 percent of dementia cases. The greatest risk factor identified was midlife hearing loss at 8.2 percent. They cited several studies, one of which indicated that there is 2x the risk of dementia with mild hearing loss, 3x the risk with moderate hearing loss and 5x the risk with severe hearing loss. They also reported that hearing loss is associated with a decrease in brain volume.
It is well recognized that hearing loss contributes to social isolation, loneliness, and decreased participation in social activities. Hearing loss also causes increased cognitive load and depression. Communication challenges from hearing loss can negatively affect personal relationships, especially with caregivers.
#5 Hearing devices can help
The Lancet commission estimated that 8.2 percent of dementia cases could be prevented or delayed by preventing mid-life hearing loss from occurring, or by treating the hearing loss with hearing aids. A key strategy for preventing hearing loss is protecting your ears from loud noise, especially in work environments. They cited several studies that indicate that hearing loss was only associated with dementia for people who do not use hearing aids.
#6 Hearing should be tested for anyone experiencing dementia symptoms
In 2017, Speech-Language and Audiology Canada (SAC) published a position statement on the role of speech pathologists and audiologists in dementia care. SAC advises that hearing loss can affect the validity of cognitive assessments. Therefore, an audiology evaluation ideally should occur prior to the cognitive tests, and the hearing status of the patient should be considered when interpreting cognitive tests. If a hearing loss is diagnosed, then appropriate strategies are recommended to compensate for the hearing loss.
Dementia and cognitive decline are complex issues. Hearing well reduces risk of developing dementia and improves overall quality of life. If hearing loss is a concern for anyone with concerns for dementia, an audiologist can help. Audiologists can diagnose and treat hearing loss and collaborate with other health professionals to help you achieve a better quality of life.